The present invention relates to grinding machines in general, and more particularly to improvements in apparatus for dressing the profiles of grinding wheels in grinding machines. Still more particularly, the invention relates to improvements in apparatus for dressing the profiles of grinding wheels of the type wherein the profile consists of iterative identical sections, as considered in the axial direction of the grinding wheel. Such grinding wheels can be used to cut teeth and tooth spaces into workpieces which are to be converted into toothed racks or the like. As a rule, the axial length of a grinding wheel which is used for cutting teeth and tooth spaces into a blank in order to convert the latter into a toothed rack or the like is quite pronounced and its profile is complementary to that of the finished product, i.e., the grinding wheel exhibits a plurality of circumferentially complete ribs alternating with circumferentially complete grooves.
Relatively long grinding wheels which can convert a workpiece into a complete toothed rack or the like, without necessitating any axial displacement of the grinding wheel with reference to the workpiece and/or vice versa, are preferred over relatively short grinding wheels for a number of reasons. Each of the iterative sections which together constitute the profile of such a grinding wheel includes a rib and a groove. Grinding wheels having such profiles are normally dressed by tools whose length matches the length of the grinding wheels. The dressing tool and the grinding wheel are set in rotary motion, the dressing tool is fed radially against the profile of the grinding wheel, and the dressing operation is completed when the dressing tool assumes a position at a certain distance from the axis of the grinding wheel. Alternatively, the dressing tool can constitute a diamond which is moved axially and radially of the profile of the grinding wheel by tracking a pattern or which performs such movements by being mounted in or on a follower advancing along a predetermined path, e.g., along a path defined by a cam groove. Each of these dressing techniques exhibits a number of drawbacks. Thus, a relatively long dressing tool is quite expensive and the means for guiding the diamond occupies a substantial amount of space.